This week we've been learning 3D modeling with Rhino 3D. Today we're taking a look at object selection and transposition.

Almost there! If you've been following along this week, you have an understanding of the software we are using, including the interface, toolbars, viewports, and construction planes. Now we need to understand how to grab an object and then move it around. Open up Rhino and let's get started.

Object Selection

Selecting an object in 3D space sounds like a pretty straight forward operation, and it is, but there are a few subtle nuances to how you do it that will greatly help your speed and precision while creating your model.

When selectiing an object, or in a lot of cases, many objects, the selection method tends to follow two basic motion paths with your mouse: left to right and right to left. This is typical for most if not all 3D modeling software.

When performing left to right selections, you are clicking and dragging to the right to completely cover what you are trying to select will select your selection, however it is important to keep in mind that it will also grab anything else that is completely surrounded by your selection window.

My favorite is the right to left option. You click and drag with your mouse to the left, and anything your selection path touches will become selectied. This is very useful for quickly selecting multiple objects or groups with more nimbleness.

This idea also works with groups of objects. By being able to rapidly select and deselect objects, you'll be well on your way to speeding up your modeling.

If you are wanting to select multiple objects in a tight cluster, holding the "SHIFT" key and clicking on objects as you need them will get you multiple selections. Rhino is pretty good about figuring out what you are trying to select, but if it isn't sure, a small prompt will come up that will allow you to select what you are intending to select. If you need to deselect something, you can hold "CTRL" and the left to right/right to left selection method will become a deselection method. This is a very useful technique when you are trying to group objects together.

If you want to select everthing in the scene, you can use the hot key combination of "CTRL + A" or if you want to deselect everything, you c an simply type "Selnone" or just hit the "ESC" key.

Object Transposition

Object transposition is just a fancy way of saying moving an object around while reorienting it in space.There are four main types of object transposition that we need to discuss. These include move, rotate, scale and mirror.

Move - With the move tool, you aren't changing any numerical values of the geometry outside of its position in space. The comand for move is "Move".

Rotate - The rotate tool is very similar to the move tool in the respect that you aren't changing any numerical values of the geometry aside from its position in space. However you are changing its orientation to one or more constructon planes. The command for rotate is "Rotate".

Scale - The scale tool is broken down into three commands - "Scale1D, Scale2D, Scale". Scale1D will scale your object on only one axis leaving the other two alone. The Scale2D command will scale your model on two axis while maintaining the scale in the third. The "Scale" command will scale your model in all three dimensions. It is worth noting that the tool works specific to whatever viewport you happen to have active. For instance, if I have a cube, and I type "Scale2D" from the top view, it will scale on the X and Y axis in the top view but leave the Z axis alone. You can see this modification happening in the other three viewports simultaneously.

Mirror - The mirror (or reflect in some programs) tool modifies your geometry in an indirect way. It makes a copy of whatever your mirroring but flips the numerical values in reverse...just like a mirror.You define the line of the mirror and it will mirror the copy exactly at the opposite angle and even distance from the mirror line. Mirror is activated by typing "Mirror".

With these 4 main tools and your new ability to select objects, you should now have a great grasp on how to move about in the Rhino workspace and be able to start manipulating objects around and build up some basic forms. Before diving too far in, I recommend checking out the Heiarchy of Geometry video.